Input: synaptics-rmi4 - re-enable IRQs in f34v7_do_reflash

Input: synaptics-rmi4 - re-enable IRQs in f34v7_do_reflash

F34 is a bit special as it reinitializes the device and related driver
structs during the firmware update. This clears the fn_irq_mask which
will then prevent F34 from receiving further interrupts, leading to
timeouts during the firmware update. Make sure to reinitialize the
IRQ enables at the appropriate times.

The issue is in F34 code, but the commit in the fixes tag exposed the
issue, as before this commit things would work by accident.

Fixes: 363c53875aef (Input: synaptics-rmi4 - avoid processing unknown IRQs)
Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Link: https://lore.kernel.org/r/20191129133514.23224-1-l.stach@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>